This invention relates to a voltage regulator for use with current limited A.C. voltage sources.
Various types of smaller size passenger-carrying vehicles such as, for example, motorcycles, trail bikes. snowmobiles, garden tractors and the like employ magneto type voltage generators for generating the vehicle ignition voltage. Where such vehicles are equipped with headlights, tail lights, brake lights, horns and the like, it is common practice to also use the magneto generated voltage to operate the auxiliary devices. One problem associated with this practice is that the output voltage of a magneto varies over a relatively wide range as the speed of the vehicle motor is varied. As a consequence, it is difficult to provide headlights, tail lights and the like which give desired brightness levels at lower operating speeds and yet which are not damaged or blown out by the larger voltages which occur throughout the higher operating speeds.
A number of possible solutions have been suggested for limiting the magneto output voltage to some predetermined level. Both peak level voltage regulators for limiting the peak value of the magneto output voltage and root-mean-square (R.M.S.) voltage regulators for limiting the R.M.S. value of the magneto output voltage have been suggested. It has been found, however, that peak level voltage regulators cause a noticeable flickering of the light at some operating speeds. Also, the lights do not provide the desired brightness at all the different operating speeds using a peak level voltage regulator. Although R.M.S. voltage regulators overcome some of the problems of the peak level voltage regulators, R.M.S. voltage regulators require an R.M.S. voltage sensing means such as a lamp or heater element and for this reason are rather expensive and subject to a higher than desirable failure rate.